The Prophet ﷺ said, "A good deed is rewarded tenfold. Fasting is for Me, and I Myself will reward it. He leaves his food and drink for My sake. Fasting is for Me, and I Myself will reward it. The breath of the fasting person is more fragrant to Allah than the scent of musk."
حدثنا محمد بن جعفر حدثنا هشام بن حسان القردوسي عن محمد بن سيرين
عن النبي ﷺ قال الحسنة بعشر أمثالها والصوم لي وأنا أجزي به يدع طعامه وشرابه من جراي الصوم لي وأنا أجزي به ولخلوف فم الصائم عند الله عز وجل أطيب من ريح المسك
Its isnad is sahih, and it has appeared many times before. This hadith is a divine hadith, and it was only not stated explicitly as such because of how well known it is.